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Page 4 of 15 Rodrigues et al. Vessel Plus 2024;8:10 https://dx.doi.org/10.20517/2574-1209.2023.109

Some guidelines suggest repair for aneurysms with a diameter threshold of 5.5 cm, saccular aneurysms
[26]
larger than 2 cm, or with a total aortic diameter greater than 5 cm . Symptomatic aneurysms or those with
rapid expansion (confirmed increase in diameter of ≥ 0.5 cm/y) should also be considered for repair
regardless of size or anatomical extent owing to higher risk for rupture. The recommendation for patients
with connective tissue disorder is correction at smaller sizes, usually between 4.5 and 5.5 cm [22,27] .

The choice of treatment modality should consider the expertise and experience of physicians, anatomy of
the patient, and surgical risk assessment. Although the endovascular approach was initially considered only
for the elderly or patients with increased surgical risk, its indications have extended to include younger and
lower-risk patients with favorable anatomy [28,29] . Older age, poor cardiopulmonary reserve, and multiple
comorbidities are features that may favor an endovascular approach, although a comprehensive evaluation
should be performed, and patients with exceedingly low life expectancy should not be considered for
[28]
repair .

Open surgical repair is preferred in patients with connective tissue disorders owing to the potential of
progressive aortic dilation, fragile landing zones, ultimately leading to low durability of the procedure.
Nevertheless, with the recent advent of “off-the-shelf” endografts, TAAA presenting urgently or emergently
can now be considered for endovascular treatment [30,31] .

DEVICE CHARACTERISTICS
Patient-specific and off-the-shelf stent-grafts
Currently, F/B-EVAR technique includes the use of either patient-specific or off-the-shelf stent grafts .
[32]
The Zenith Fenestrated AAA Endovascular Graft (ZFEN) was the first patient-specific fenestrated
manufactured device to be commercially approved in the United States in April 2012. However, its design
accepts the maximum incorporation of three target vessels, resulting in limited use to patients with short
neck infrarenal or juxtarenal abdominal aortic aneurysms, excluding those with pararenal aneurysms (PRA)
and TAAAs . The use of fenestrated and branched endografts with four or more vessels has been restricted
[33]
in the United States to clinical trials or institutions with physician-sponsored investigational device
exemption (PS-IDE) protocols for patient-specific devices. Moreover, the manufacturing process of these
endografts is time-consuming, taking 4-6 weeks, limiting their use in urgent or emergent situations . In
[34]
this setting, physician-modified endografts (PMEGs) emerge as an option to overcome these obstacles using
off-the-shelf endografts which are modified by the surgeon to create fenestrations and directional branches
in a sterile manner before implantation to match the anatomy of the patient and clinical needs. One should
be aware of the critical importance of the modification planning and technique execution that rely entirely
on the surgeon.

Outcomes of PMEGs in comparison with patient-specific manufactured devices (PSMD) have
demonstrated it as an effective and safe endovascular option. Data of 316 consecutive treated patients were
analyzed, 145 treated with PMEGs (84 PRAs, 26 extent IV, and 35 extent I-III TAAAs), and 171 with PSMD
[32]
(88 PRAs, 42 extent IV, and 41 extent I-III TAAAs) . Aneurysms repaired with PMEGs were significantly
larger, and patients had more chronic pulmonary and kidney disease, and higher comorbidity severity
scores. Technical success was high in both groups, slightly lower for PMEGs (98% vs. 99.5%). Early
(< 30 days) mortality was 5.5% for PMEGs and zero for PSMDs (P = 0.0018), likely reflecting surgeon and
center learning curves. Patients treated with PMEGs had significantly more major adverse events (48% vs.
23%), with a significant fraction of those related to bleeding from access sheaths, which has been mitigated